Opposition to fracking will propel the Green Party to success in the European elections, its leader declared as she said the winter floods had delivered the UK a "powerful" warning about climate change.

Natalie Bennett said it would be one of the most significant issues at May's European elections as she pledged to "fight" for a voice in a planned TV leaders' debate.

She accused David Cameron of "abandoning" whole areas of the country to floods, comparing the devastation with that suffered by mining communities in the 1980s under Margaret Thatcher.

And she renewed calls for Owen Paterson to be sacked as Environment Secretary over his handling of the floods and the "scientific illiteracy" of the heavily- criticised badger cull.

Addressing the party's spring conference in Liverpool, she put opposition to fracking - the controversial Government-backed process for exploiting shale gas reserves - at the centre of her pitch to voters.

Opponents fear it will damage the countryside, pollute water supplies and make it harder to cut emissions to tackle climate change.

It has sparked protest movements in areas set to be targeted for drilling - with the party's sole MP Caroline Lucas arrested during one demonstration.

"On fracking, the Green Party view represents the majority view of the British public," she said.

"That's like so many other issues, from bringing the railways back into public hands, to making the minimum wage a living wage and keeping a publicly-owned and publicly-run NHS.

"Yet elsewhere on Britain's political spectrum we've got David Cameron and George Osborne determined to pursue the fracking fantasy, making claims about cheap and instant gas that even the frackers are astonished at.

"We've got a Lib Dem Energy Secretary who said 'I love shale gas' twice, just in case anyone was too shocked to really take it in the first time.

"And a Labour Party that's in favour of fracking, kind of, sort of, well, as long as that doesn't upset anyone in this audience, in which case we might take a different position.

"Fracking is an issue I'm convinced we will win on - in small part due to the logic of our position, in larger part due to the strength, the passion, the determination of our anti-fracking protesters.

The impact of extreme weather and a recent United Nations report pinning the blame more firmly than ever on human activity has persuaded more people than ever about the need to change, she said.

"Britain's record winter rainfall, the massive droughts in California and Latin America, Australia's heatwaves, come together to deliver a powerful message - which the opinion polls show the British people have heard loud and clear - that climate change is a reality, here, with us today," she said.

"Its threat is enormous and can no longer be ignored."

She urged Mr Cameron - who has firmly connected the floods to climate change - to remove Mr Paterson.

"We can no longer have an Environment Secretary who denies the reality of climate change.

"Having a man in his role who's so clearly demonstrated his scientific illiteracy with the badger cull is astonishing," she said amid reports that an expert review found the pilot neither effective nor humane.

"But having him in charge of our preparation for, and prevention of, climate change is a huge black mark on your record, Mr Cameron."

In a direct attack on the Prime Minister, she went on: "It's a story of Tory neglect that runs on: as Thatcher abandoned the mining communities, David Cameron has abandoned whole areas to floods."

The party has had two MEPs since 1999 and secured 8.7% of the vote in the last elections to the European Parliament in 2009, topping the ballot in several cities.

Deputy Prime Minister Nick Clegg is set for a televised showdown with UK Independence Party leader Nigel Farage ahead of the May 22 poll and Ms Bennett believes she deserves to join them.

"You might have noticed that two of Britain's noisiest political minnows, two of yesterday's men, Nigel Farage and Nick Clegg, are planning on having a debate on Europe," she said.

Mr Farage believes pulling out of the EU would " magically restore some golden age" while the Liberal Democrat leader had betrayed his party's green credentials by supporting fracking in the UK, she said.

"I say today to the television producers, to the media executives, to the public, that if there's a debate on Europe, the Green Party, I must be there, and will fight to be there."